Cystinosis is a rare, autosomal recessive disease caused by intra-lysosomal accumulation of the amino acid cysteine within various tissues, including the spleen, liver, lymph nodes, kidney, bone marrow, and eyes. Nephropathic cystinosis is associated with kidney failure that necessitates kidney transplantation. A specific treatment for nephropathic cystinosis is the sulfhydryl agent cysteamine. Cysteamine has been shown to lower intracellular cystine levels, thereby reducing the rate of progress of kidney failure in children.
Cysteamine, and pharmaceutically acceptable salts thereof, may also be administered for the treatment of other metabolic and neurodegenerative diseases, including non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), Huntington's disease, Parkinson's disease, Rett Syndrome, cystic fibrosis, and others; used as free radical and radioprotectants; used as hepato-protectant agents.
Enterically-coated cysteamine compositions for increasing delivery of cysteamine to the small intestine and resulting in less frequent dosing compared to non-enteric-coated cysteamine have been described. See, e.g., WO 2014/204881, WO 2007/089670, and U.S. Pat. Nos. 8,026,284, 9,198,882, 9,192,590, 9,173,851, and 9,233,077.
In some cysteamine pharmaceutical compositions, cysteamine is not chemically stable and degrades into several impurities over time.